+/**
+ * \brief Acquire a heavy mutex
+ * \param Mutex Mutex to acquire
+ *
+ * This type of mutex checks if the mutex is avaliable, and acquires it
+ * if it is. Otherwise, the current thread is added to the mutex's wait
+ * queue and the thread suspends. When the holder of the mutex completes,
+ * the oldest thread (top thread) on the queue is given the lock and
+ * restarted.
+ */
+void Mutex_Acquire(tMutex *Mutex)
+{
+ tThread *us = Proc_GetCurThread();
+
+ // Get protector
+ SHORTLOCK( &Mutex->Protector );
+
+ //Log("Mutex_Acquire: (%p)", Mutex);
+
+ // Check if the lock is already held
+ if( Mutex->Owner ) {
+ SHORTLOCK( &glThreadListLock );
+ // - Remove from active list
+ us = Threads_RemActive();
+ us->Next = NULL;
+ // - Mark as sleeping
+ us->Status = THREAD_STAT_MUTEXSLEEP;
+ us->WaitPointer = Mutex;
+
+ // - Add to waiting
+ if(Mutex->LastWaiting) {
+ Mutex->LastWaiting->Next = us;
+ Mutex->LastWaiting = us;
+ }
+ else {
+ Mutex->Waiting = us;
+ Mutex->LastWaiting = us;
+ }
+ #if 0
+ {
+ int i = 0;
+ tThread *t;
+ for( t = Mutex->Waiting; t; t = t->Next, i++ )
+ Log("[%i] (tMutex)%p->Waiting[%i] = %p (%i %s)", us->TID, Mutex, i,
+ t, t->TID, t->ThreadName);
+ }
+ #endif
+
+ SHORTREL( &glThreadListLock );
+ SHORTREL( &Mutex->Protector );
+ while(us->Status == THREAD_STAT_MUTEXSLEEP) Threads_Yield();
+ // We're only woken when we get the lock
+ us->WaitPointer = NULL;
+ }
+ // Ooh, let's take it!
+ else {
+ Mutex->Owner = us;
+ SHORTREL( &Mutex->Protector );
+ }
+
+ #if 0
+ extern tMutex glPhysAlloc;
+ if( Mutex != &glPhysAlloc )
+ LogF("Mutex %p taken by %i %p\n", Mutex, us->TID, __builtin_return_address(0));
+ #endif
+}
+
+/**
+ * \brief Release a held mutex
+ * \param Mutex Mutex to release
+ */
+void Mutex_Release(tMutex *Mutex)
+{
+ SHORTLOCK( &Mutex->Protector );
+ //Log("Mutex_Release: (%p)", Mutex);
+ if( Mutex->Waiting ) {
+ Mutex->Owner = Mutex->Waiting; // Set owner
+ Mutex->Waiting = Mutex->Waiting->Next; // Next!
+ // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
+ // 2010-10-02 21:50 - Comemerating the death of the longest single
+ // blocker in the Acess2 history. REMEMBER TO
+ // FUCKING MAINTAIN YOUR FUCKING LISTS DIPWIT
+ if( Mutex->LastWaiting == Mutex->Owner )
+ Mutex->LastWaiting = NULL;
+
+ // Wake new owner
+ SHORTLOCK( &glThreadListLock );
+ if( Mutex->Owner->Status != THREAD_STAT_ACTIVE )
+ Threads_AddActive(Mutex->Owner);
+ SHORTREL( &glThreadListLock );
+ }
+ else {
+ Mutex->Owner = NULL;
+ }
+ SHORTREL( &Mutex->Protector );
+
+ #if 0
+ extern tMutex glPhysAlloc;
+ if( Mutex != &glPhysAlloc )
+ LogF("Mutex %p released by %i %p\n", Mutex, Threads_GetTID(), __builtin_return_address(0));
+ #endif
+}
+
+/**
+ * \brief Is this mutex locked?
+ * \param Mutex Mutex pointer
+ */
+int Mutex_IsLocked(tMutex *Mutex)
+{
+ return Mutex->Owner != NULL;
+}
+
+/**
+ * \brief Initialise the semaphore
+ * \param Value Initial value of the semaphore
+ * \param Label Symbolic name
+ */
+void Semaphore_Init(tSemaphore *Sem, int Value, const char *Label)
+{
+ Sem->Value = Value;
+ Sem->Name = Label;
+}
+
+/**
+ * \brief Acquire a "item" from the semaphore
+ */
+void Semaphore_Wait(tSemaphore *Sem)
+{
+ tThread *us;
+
+ SHORTLOCK( &Sem->Protector );
+ if( Sem->Value > 0 ) {
+ Sem->Value --;
+ SHORTREL( &Sem->Protector );
+ return ;
+ }
+
+ SHORTLOCK( &glThreadListLock );
+
+ // - Remove from active list
+ us = Threads_RemActive();
+ us->Next = NULL;
+ // - Mark as sleeping
+ us->Status = THREAD_STAT_SEMAPHORESLEEP;
+ us->WaitPointer = Sem;
+
+ // - Add to waiting
+ if(Sem->LastWaiting) {
+ Sem->LastWaiting->Next = us;
+ Sem->LastWaiting = us;
+ }
+ else {
+ Sem->Waiting = us;
+ Sem->LastWaiting = us;
+ }
+
+ SHORTREL( &glThreadListLock );
+ SHORTREL( &Sem->Protector );
+ while(us->Status == THREAD_STAT_MUTEXSLEEP) Threads_Yield();
+ // We're only woken when there's something avaliable
+ us->WaitPointer = NULL;
+}
+
+/**
+ * \brief Add an "item" to the semaphore
+ */
+void Semaphore_Signal(tSemaphore *Sem)
+{
+ SHORTLOCK( &Sem->Protector );
+ Sem->Value ++;
+
+ if( Sem->Waiting )
+ {
+ tThread *toWake = Sem->Waiting;
+
+ Sem->Waiting = Sem->Waiting->Next; // Next!
+ // Reset ->LastWaiting to NULL if we have just removed the last waiting thread
+ if( Sem->Waiting == NULL )
+ Sem->LastWaiting = NULL;
+
+ // Wake new owner
+ SHORTLOCK( &glThreadListLock );
+ if( toWake->Status != THREAD_STAT_ACTIVE )
+ Threads_AddActive(toWake);
+ SHORTREL( &glThreadListLock );
+
+ // Decrement (the value is now "owned" by `toWake`)
+ Sem->Value --;
+ }
+ SHORTREL( &Sem->Protector );
+}
+